A useful technology known as thermo-chemical regenerator (TCR) for utilizing the heat in flue gases that are produced in furnaces such as glassmelting furnaces is described in U.S. Pat. No. 6,113,874. In this technology, flue gas is passed through a regenerator which is heated by the flue gas. A portion of the flue gas that emerges from this regenerator is mixed with gaseous fuel and the resulting mixture is fed into another regenerator which has been heated sufficiently so that the mixture is converted into syngas by virtue of an endothermic reaction of components in the mixture. The resulting syngas is then fed from the regenerator in which it formed, into the furnace to be combusted. At appropriate intervals, the regenerators in which the operations are performed are reversed.
Whereas this technology has in general many attractive features, the present inventors have unexpectedly found ways to improve the efficiency of this technology.